.m400{
    width: 500px;
    margin: auto;
}
.ltab_btn {
    margin-bottom: 1px;
    li{
        list-style: none;
        display: inline-block;
        width: 100px;
        // height: 400px;
        line-height: 40px;
        text-align: center;
        font-size: 14px;
        cursor: pointer;
        &.cur{
            background: #f60;
            color: #fff;
        }
    }
}
.ltab_box {
    li{
        height: 200px;
        border: 1px solid red;
        display: none;
        &.cur {
            display: block;
        }
    }
}